help.
a student plans to investigate how different factors affect the rotation rate of a hand-made motor when connected to a battery. The student will test a different variable in each investigation: the voltage of the battery (V), the number of loops used in the wire coil, and the number of magnets used below the loops. The first table shows details and predictions for investigation
How should the student design investigation 3 to finish testing the factors that affect the rotation rate of a motor?

1 mole is equal to 6.0220 x 1023 atoms of any element.

steps that are followed in taking a stratified random sample are

i. Take a sample of size n/k from each strata, where n is the sample size and k is the number of strata

iv. Take a systematic sample from the population as a whole. Take random samples from each strata.

Stratified random sampling is a sampling method that divides the population into smaller groups called layers. Groups or hierarchies are organized based on the common characteristics or attributes of the members in the group. The process of dividing the population into groups is called hierarchization.

Stratified Random Sample Example:

Suppose a research team wants to determine a GPA for a college student in the United States. The research team is having a hard time collecting data from all 21 million college students. We decided to use 4,000 students to extract a random sample of the population.

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Answer:

7.62 plug into the equation for freezing

0= 592/7.62x x 90

0 = 77.69x x 90

x=0

therefore according to balton's law, it is required to have 0 + 27.222222222 (balton's number) to get the energy required.

answer is 27.222222 rounded 27. cheers.

The Answer is d. half a trillion tons

What is fossil fuels?

Fossil fuel is a term for non-renewable energy sources such as coal, crude oil, coal products, derived gas, natural gas, petroleum products and non-renewable wastes. These fuels originate from plants and animals that existed in the geological past (millions of years ago).

When fossil fuels are burned, they release large amounts of carbon dioxide, a greenhouse gas, into the atmosphere. Greenhouse gases trap heat in the atmosphere, causing global warming.

I suppose the question is :

How much carbon dioxide have we emitted into the atmosphere by burning fossil fuels since the industrial revolution?

a- a million tons

b- a billion tons

c- half a billion tons

d- half a trillion tons

e- a trillion tons

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Answer:

d. forced migration

Explanation:

Certain hazardous occurrences affect living organisms in their natural habitat. One of those occurrences is forest fire. Forest fire or vegetation fire is an uncontrollable break out of fire in a vegetation, affecting the inhabitants of the area.

The occurrence of a forest fire will lead to a forced migration of organisms from their natural habitat. Animals and other mobile organisms will be forced to leave behind their devastating habitat and migrate to a less threatened area in order to survive.

Answer:

D

Explanation:

The guy above is correct but I’m saying this for those who don’t want an explanation

Answer:

Dissolving is when the solute breaks up from a larger crystal of molecules into much smaller groups or individual molecules. This break up is caused by coming into contact with the solvent. In the case of salt water, the water molecules break off salt molecules from the larger crystal lattice.

Explanation:

Answer:

Gases can dissolve in water. The dissolving of a gas in water depends on the interaction between the molecules of the gas and the water molecules. The amount of gas that can be dissolved in water depends on the temperature of the water. More gas can dissolve in cold water than in hot water.

Explanation:

To convert an aldehyde to a carboxylic acid, oxidation of the aldehyde functional group is required.

There are several reagents that can be used for this conversion:

1. Strong Oxidizing Agents:

  - Potassium permanganate (KMnO4): In the presence of acidic conditions, KMnO4 can oxidize aldehydes to carboxylic acids.

  - Chromic acid (H2CrO4): It is a strong oxidizing agent that can convert aldehydes to carboxylic acids.

2. Tollens' Reagent:

  Tollens' reagent, also known as silver mirror reagent, is a solution of silver nitrate (AgNO3) and ammonia (NH3) in water. It can oxidize aldehydes to carboxylic acids under mild conditions. It produces a silver mirror on the inner surface of the reaction vessel.

3. Jones Reagent:

  Jones reagent consists of a solution of chromium trioxide (CrO3) in diluted sulfuric acid (H2SO4). It is a strong oxidizing agent that can convert aldehydes to carboxylic acids.

These are some commonly used reagents to convert aldehydes to carboxylic acids through oxidation. The choice of reagent may depend on factors such as reaction conditions, desired selectivity, and other functional groups present in the molecule.

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To solve this problem, we can use Henry's Law, which relates the solubility of a gas in a liquid to the partial pressure of the gas above the liquid. The equation for Henry's Law is:
C = kH*P
where C is the concentration (or solubility) of the gas in the liquid, kH is the Henry's Law constant, and P is the partial pressure of the gas.

We are given the Henry's Law constant for sulfur hexafluoride at 25 °C, which is 2.4×10−4 mol/(L⋅atm). We are also given the partial pressure of sulfur hexafluoride, which is 1.90 atm.
We can use these values to calculate the solubility of sulfur hexafluoride in water at 25 °C:
C = kH*P
C = (2.4×10−4 mol/(L⋅atm)) * (1.90 atm)
C = 4.56×10−4 mol/L

Therefore, the solubility of sulfur hexafluoride in water at 25 °C and a partial pressure of 1.90 atm is 4.56×10−4 mol/L.
The solubility of sulfur hexafluoride in water at 25°C and a partial pressure of 1.90 atm can be calculated using Henry's law constant, which is 2.4 × 10⁻⁴ mol/(L⋅atm). According to Henry's law, solubility = Henry's law constant × partial pressure. In this case, solubility = (2.4 × 10⁻⁴ mol/(L⋅atm)) × 1.90 atm. By calculating this, we get the solubility of sulfur hexafluoride in water at 25°C and 1.90 atm as 4.56 × 10⁻⁴ mol/L.

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The volume would be explanation times explanation because the explanation is the explanation

Explanation:

Answer:

\(\boxed {\boxed {\sf v=12 \ mL}}\)

Explanation:

Grace found the volume of the rock using water displacement.

To calculate the volume, we must subtract the initial volume from the final volume.

\(v_f-v_i\)

The initial or original volume is 20 milliliters.

The final or new volume, after the rock is added to the water, is 32 milliliters.

\(v_f=32 \ mL\\v_i=20\ mL\)

Substitute the values into the formula and subtract.

\(32 \ mL-20 \ mL\)

\(12 \ mL\)

The volume of the rock is 12 milliliters.

The compressibility of a gas is determined by the relationship between its volume and pressure measurements, with the compressibility factor providing a quantitative measure of this relationship and deviations from ideal gas behavior.

The compressibility of a gas is defined by the relationship between its volume and pressure measurements. Compressibility is a property that describes how easily a gas can be compressed or expanded under the influence of external pressure.

When a gas is subjected to an increase in pressure, its volume tends to decrease, indicating compressibility. On the other hand, when the pressure on a gas is reduced, its volume tends to increase, indicating expansibility. The compressibility factor (Z) is commonly used to quantify the compressibility of a gas.

Mathematically, compressibility is expressed by the equation:

Z = PV/RT,

where Z is the compressibility factor, P is the pressure, V is the volume, R is the ideal gas constant, and T is the absolute temperature.

The compressibility factor provides information about deviations from ideal gas behavior. For an ideal gas, Z equals 1 at all pressures and temperatures. However, real gases often deviate from ideal behavior due to intermolecular interactions and non-ideal conditions.

At low pressures and high temperatures, most gases behave close to ideal gas behavior and have a compressibility factor close to 1. However, at high pressures and/or low temperatures, gas molecules come closer together, and intermolecular interactions become significant, causing deviations from ideal behavior and resulting in a compressibility factor different from 1.

By studying the compressibility factor as a function of pressure and temperature, one can gain insights into the behavior of gases under various conditions, including phase transitions, critical points, and the presence of attractive or repulsive intermolecular forces.

In summary, the compressibility of a gas is determined by the relationship between its volume and pressure measurements, with the compressibility factor providing a quantitative measure of this relationship and deviations from ideal gas behavior.

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The molecular formula of the unknown compound is C2H2O2.

To determine the molecular formula of the unknown compound, we need to calculate the empirical formula first and then find the multiple of its subscripts to obtain the molecular formula.

Given:

Percentage of carbon = 40.0%

Percentage of hydrogen = 6.7%

Percentage of oxygen = 53.3%

Molecular mass = 60.0 g/mol

Step 1: Convert the percentages to grams.

Assuming we have 100 grams of the compound:

Mass of carbon = 40.0 g

Mass of hydrogen = 6.7 g

Mass of oxygen = 53.3 g

Step 2: Convert the masses to moles using the molar masses of the elements.

Molar mass of carbon = 12.01 g/mol

Molar mass of hydrogen = 1.008 g/mol

Molar mass of oxygen = 16.00 g/mol

Number of moles of carbon = Mass of carbon / Molar mass of carbon

= 40.0 g / 12.01 g/mol

= 3.332 mol

Number of moles of hydrogen = Mass of hydrogen / Molar mass of hydrogen

= 6.7 g / 1.008 g/mol

= 6.648 mol

Number of moles of oxygen = Mass of oxygen / Molar mass of oxygen

= 53.3 g / 16.00 g/mol

= 3.331 mol

Step 3: Determine the empirical formula by dividing the moles by the smallest value.

Dividing the moles of carbon, hydrogen, and oxygen by 3.331 gives approximately 1 for each element.

So, the empirical formula of the compound is CHO.

Step 4: Determine the multiple of the subscripts to obtain the molecular formula.

To find the multiple, we divide the molecular mass by the empirical formula mass.

Molecular mass = 60.0 g/mol

Empirical formula mass = (12.01 g/mol) + (1.008 g/mol) + (16.00 g/mol) = 29.018 g/mol

Multiple = Molecular mass / Empirical formula mass

= 60.0 g/mol / 29.018 g/mol

= 2.07

Rounding to the nearest whole number, we get 2.

Therefore, the molecular formula of the unknown compound is C2H2O2.

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Answer:

70..... I think

Explanation:

Cuz if the bus travels 35 km every 30 mins this means that it travels 70 km per hour

Answer:

Explanation:

Image result for Summarize: What do you think would happen to the convection currents in the atmospheres and along the coastlines of the surface of the Earth warmed up? Do you think this could have any affect on the convection in the mantle? Why or why not? Your answer should be at least 3 sentences in length,

As the magma cools and solidifies, the convection currents will stop and the Earth will become geologically dead.

The limiting agent is AgNO3. 2 moles of AgNO3 plus 1 mole of Cu equals 2 moles of Ag plus 1 mole of Cu.(NO3)2. To find the answer, compare the mole ratio in the problem to the mole ratio in the chemical equation.

Individual water molecules may behave as catalysts or reactants during the reaction. Through interactions between solutes and solvents and solvent rearrangement, water can influence variations in the free energy of activation.

When atoms establish or break chemical bonds, chemical processes take place. Reactants are the substances that begin a chemical reaction, while products are the compounds that are created as a result of the reaction.

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Therefore, the sample of lead weighs 82.3 g.

Since both samples contain the same number of atoms, we can assume they have the same molar amount.

The molar mass of vanadium is 50.94 g/mol, so the number of moles in the vanadium sample is:

20.3 g / 50.94 g/mol = 0.398 mol

Since the samples contain the same number of atoms, the number of moles of lead in the other sample is also 0.398 mol.

The molar mass of lead is 207.2 g/mol, so the mass of the lead sample is:

0.398 mol x 207.2 g/mol = 82.3 g

Therefore, the sample of lead weighs 82.3 g.

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Dew forms on the grass in the early morning due to the process of condensation.

During the day, the sun heats up the ground and the air around it. When the sun sets, the ground and the air begin to cool down. As the air cools, its ability to hold moisture decreases. When the temperature drops below the dew point, which is the temperature at which the air is saturated and cannot hold any more moisture, the excess moisture in the air condenses into liquid water droplets. These droplets then collect on cool surfaces, such as grass, forming dew.

The grass is a good surface for dew to form on because it is usually cooler than the surrounding air due to transpiration, the process by which water evaporates from the leaves and stems of plants. This causes the grass to cool down faster than the air around it, making it more likely for dew to form on its surface.

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Explanation:

This is due to the reason that in case of inert gases, the outer shell is complete and it has hence maximum electronic repulsion. Moreover in case of inert gases, the atomic size is expressed in terms of Vanderwaal’s radius because, noble gases do not form covalent bonds while other form covalent bonds and hence their atomic radii is expressed in covalent radius. Generally atomic size decreases while moving from left to right in the periodic table. But in the case of noble gases, they have comparatively higher atomic size than corresponding halogens because of the reason that vanderwaal’s radii (present in noble gases) is much larger than ionic and covalent radii (present in other elements). Thus as, Vanderwaal’s radius is greater than covalent radius, the atomic size of noble gases is larger than other elements of same period.

The placement of a plastic coating (a, b, c, or d below) that could be used to prevent galvanic corrosion would depend on the type of plastic coating being used and the specifics of the joined copper and iron pieces that are exposed to salt water conditions.

Generally, a plastic coating should be applied to prevent any direct contact between the copper and iron pieces. Placement “a” and “b” could both be used, as they would create a barrier between the two pieces, while placement “c” and “d” would not be as effective because there would still be direct contact between the two pieces.

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The optimum velocity of the carrier gas is 0 cm s⁻¹.To determine the optimum velocity of the carrier gas, we need to consider the Van Deemter equation:

H = A + B/u + C*u

In this equation, H represents the plate height (HETP) and u represents the flow velocity (linear flow rate) of the carrier gas.

To find the optimum velocity, we need to minimize the plate height. The plate height is minimized when the B/u term in the equation is at its minimum value. This occurs when B/u = 0.

Given that B = 0.25 cm s⁻¹, we can set up the equation:

0.25 cm s⁻¹ / u = 0

Solving for u, we find:

u = 0.25 cm s⁻¹ / 0

u = 0 cm s⁻¹

Therefore, the optimum velocity of the carrier gas is 0 cm s⁻¹.

It's important to note that in this case, the optimum velocity is zero because the B term in the Van Deemter equation is zero. This implies that the plate height is solely determined by the A and C terms, and the carrier gas velocity does not play a significant role in minimizing the plate height.

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Incomplete Question

(b) For a certain GC system, the parameters A, B and C terms have the numerical values of 0.012 cm, 0.25 cm s¹ and 0.0022 s¹, respectively for the Van Deemter equation, where the flow velocity (aka. linear flow rate, u) has the unit of cm s¹ and the plate height (HETP or H) is a measured in centimeters.

Task: Write

(i)What is the optimum velocity of the carrier gas? Be careful with significant figures (2 pts)

Radioactive contamination refers to the presence of radioactive material in a location where it may pose a potential risk or harm to individuals or the environment. The correct answer is C) radioactive contamination.

It occurs when radioactive substances are released or deposited in an area, leading to the contamination of surfaces, objects, or organisms with radioactive particles or radiation. This contamination can occur as a result of accidents, spills, leaks, or improper handling of radioactive materials. Radioactive contamination can have serious health consequences as exposure to radioactive substances can lead to radiation sickness, genetic damage, or an increased risk of developing cancer. It is crucial to properly manage and mitigate radioactive contamination to ensure the safety of individuals and the environment. This involves employing protective measures such as containment, decontamination procedures, and implementing strict protocols for handling and disposing of radioactive materials.

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Two or more substances which are not chemically combined but only mixed together form a mixture.

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Answer:

Density, \(d=19.3\ g/cm^3\)

Explanation:

Given that,

Mass of gold is 38.6 g

Volume, V = 2 cm³

We need to find the density of gold cube. The density of an object is defined as how much mass it has divided by its volume. So,

\(d=\dfrac{38.6\ g}{2\ cm^3}\\\\d=19.3\ g/cm^3\)

So, the density of the cube of gold is \(19.3\ g/cm^3\).

The answer would be +208 J.

Answer:

1) F. harmful gases and solid particles that enter the atmosphere

2) C. pollutant gases react with water vapor

3) B. mixture of smoke, gas, and fog

4) E. sunlight interacts with pollutant gases

5) A. gradual increase in the overall temperature of the earth

6) D. gases are trapped by heat and raise the temperature of the atmosphere

hope this helps

Answer:

Sublimation

Explanation:

Answer:the pressure inside the flask will increase rapidly, and this can cause the flask to implode.

Explanation:)

Answer:

As the pressure increases the boiling point increases.

(a) The number of moles of oxygen gas (O₂) that reacted is 0.00325 mol.

(b) When the experiment is repeated without a lid on the crucible, the magnesium oxide produced will react with any oxygen present in the air.

(a) To calculate the number of moles of oxygen gas (O₂) that reacted, we need to first determine the number of moles of magnesium that reacted using its atomic mass:

Mass of magnesium (Mg) = 0.12 g

Atomic mass of Mg = 24.31 g/mol (from periodic table)

Number of moles of Mg = Mass of Mg / Atomic mass of Mg

= 0.12 g / 24.31 g/mol

= 0.00494 mol

The balanced chemical equation for the reaction between Mg and O₂ to produce MgO is:

2Mg + O₂ → 2MgO

From the equation, we can see that 2 moles of Mg react with 1 mole of O₂ to produce 2 moles of MgO.

Therefore, the number of moles of O₂ that reacted can be calculated as follows:

Number of moles of MgO produced = Mass of MgO / Molar mass of MgO

= 0.20 g / (24.31 g/mol + 16.00 g/mol)

= 0.00650 mol

Since 2 moles of MgO are produced from 1 mole of O₂, the number of moles of O₂ that reacted can be calculated as:

Number of moles of O₂ = Number of moles of MgO produced / 2

= 0.00650 mol / 2

= 0.00325 mol

(b) When the experiment is repeated without a lid on the crucible, the magnesium oxide produced will react with any oxygen present in the air. This will cause the mass of magnesium oxide produced to be greater than when the experiment was conducted with a lid on the crucible, as more oxygen will react with the magnesium.

Additionally, any water vapor or other gases present in the air may also react with the magnesium oxide, further affecting the mass of the final product. Therefore, the mass of magnesium oxide produced will be different without a lid on the crucible due to the presence of additional reactants in the air.

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Answer:Main Answer:

The mass of CO2 released in the production of 123,000 g of H2 gas is 265,200 g.

Explanation: From the given equation, we can see that the production of 4 moles of H2 requires the combustion of 1 mole of CH4, resulting in the release of 2 moles of H2O and 1 mole of CO2. The molar mass of H2 is 2 g/mol, and the molar mass of CO2 is 44 g/mol. Therefore, the mass of CO2 released in the production of 123,000 g of H2 is (123,000/2) x (1/4) x 44 = 265,200 g.